In conventional Winchester disk drives, a read/write head or transducer assembly "flies" upon an air bearing or cushion in very close proximity to the rotating surface of the data storage disk. The disk surface carries a thin film magnetic material having a multiplicity of magnetic storage domains that may be recorded and read back by the head. The transducer assembly, which can be any conventional, combination of transducers, sliders and load beams, is positioned and supported proximate the surface of the data storage disk using an actuator. The combination of the transducer assembly and the actuator is known as the transducer actuator or actuator assembly. The actuator supports the load beams and sliders and accurately positions the transducers above the surface of the disk within a "data area" to read and write data from/to the disk. When not in operation, the actuator assembly remains stationary in a "landing zone" along the inner diameter of the disk wherein the transducer rests on the surface of the disk. An actuator latch prevents the actuator assembly from moving into the data area during non-operation. The latch, may include an air vane portion which extends over the surface of the disk and pivots about an axis of rotation. As airflow generated by the rotating disk overcomes a biasing force from e.g. a magnet and moves the latch to release the actuator assembly. Such actuator latches are known as "airlocks".
The disk drive industry is moving towards the adoption of extremely smooth media (rotating recording disk) to enable the read write slider element to fly closer to the magnetic recording disk surface. Although closer flying proximity is desirable for improved read/write performance, a problem remains that if the slider were to come into contact with the smooth surface while the disk is not spinning, a "Jo-block" effect between the smooth disk surface and the slider could effectively adhere the two together. In response to this problem, the disk manufacturing industry has developed what is referred to as "zone textured" media. As the name implies, the landing zone is textured to reduce the coefficient of friction between the slider and disk. Texturing enables the slider to break free of the disk during disk spin-up, without detrimentally affecting the slider and/or disk. Texturing may also be applied to air bearing surfaces of the slider.
FIG. 1 shows a plan view of a somewhat simplified disk drive, incorporating a typical air vane actuator latch 11. The latch 11 includes an air vane portion 12, depicted in a latched position, wherein a transducer 4 rests on a disk 13 at a landing zone 2. As shown in FIG. 1, in order for the transducer 4 to enter a data storage area 3 of the disk 13, air vane actuator latch 11 must first rotate clockwise, to disengage from the actuator assembly 17, followed by a clockwise rotation of the actuator assembly 17.
The latch 11 is specifically designed to be mass balanced about its axis of rotation so that linear shocks will not cause it to rotate and possibly permit the actuator 17 to escape from its latched position. In practice, conventional rotary airlock actuator latches have proven to be reasonably reliable in keeping the actuator assembly latched, provided that the input shock is linear in nature.
However, conventional air vane actuator latching mechanisms such as that of FIG. 1 offer less protection against rotary shock forces. When subjected to rotary shock, which may be described as sudden and rapid rotational movement of the disk drive 10, the respective inertia of the air vane latch 11 and the actuator assembly 17 tend to maintain their relative angular orientation, rather than rotate with a disk drive base 18. Thus, if the base 18 is suddenly rotated counterclockwise, the air vane latch 11 and the actuator 17, will tend to rotate with the base 18. In effect, the latch 11 and actuator 17 undergo a clockwise rotation with respect to the base 18, resulting in the orientation shown in FIG. 2 and an unwanted release of the actuator assembly 17. When the disk 13 is not rotating, release of actuator 17 causes unwanted contact between the slider and the data storage area 3. (FIG. 2 shows this problem) In practice, it is fairly easy to cause the prior air vane latch to fail in response to certain rotary shock forces, more frequently present especially in portable and laptop computers.
Thus, there exits a hitherto unsolved need for an improved, simple and cost efficient latching mechanism which can effectively protect against rotary as well as linear shock forces.